Numerous types of conveyors have been used in the prior art to transfer or load sheet material. In the manufacture of plywood, a plurality of veneers are laid one upon another at a plurality of locations along a glue line conveyor. At these locations a sheet transfer device is used to transfer an individual sheet of veneer from a stack of sheets to the conveyer.
One type of transfer mechanism or conveyor supports a sheet being conveyed by its bottom surface and feeds the sheet off the end of the conveyor onto a concurrently moving primary conveyor disposed below it. Such a transfer device is shown in U.S. Pat. No. 3,504,732 issued to Robert J. Slagle, et al. on Apr. 7, 1970.
Another type of transfer device deposits a transferred sheet above a desired location and allows the sheet to float downward. The present invention is directed to an improvement in this type of device. One such transfer device is disclosed in U.S. Pat. No. 3,490,614 issued to Russell W. Wilson, et al. on Jan. 20, 1970. The transfer device disclosed in U.S. Pat. No. 3,490,614 lifts an uppermost sheet from a stack at a first station with a vacuum or suction lifting force, supports the sheet in a lifted position by means of the vacuum and transfers the sheet to a second station. While maintaining the vacuum lift, a releasing force is applied to the sheet in a direction opposite to that in which the vacuum is supplied. The releasing force is greater than the force exerted by the vacuum lift and, hence, the sheet is separated from the vacuum lift and allowed to float downwardly to a desired location at the second station. A lengthwise edge of the sheet is aligned at the second station. A floating weight assembly is provided for stablizing the sheet as it floats downwardly. The weight assembly, however, utilizes only two discrete shoes adjacent the edges being aligned for providing downward pressure upon the sheet.